Light bulb base extractor

ABSTRACT

A tool for extracting the base of a broken light bulb from an electric socket is disclosed. The tool has a plurality of pointed knife-like blades which are pivotally mounted within the tool to swing downwardly and radially outwardly, thus defining a radially expanding arcuate movement, for engaging the inner surfaces of a light bulb base from which the globe has been broken off or removed.

1111 3,898,896 51 Aug. 12, 1975 United States Patent [191 Suhay [54] LIGHT BULB BASE EXTRACTOR 1,677 507 7/1928 Vock et al. 30/107 2,728,138 12 1955 G 30 I08 [76] Inventor: Laszlo Suhay, 1743 Payne, Findlay, m 1

' Ohio 45840 Primary Examiner-James L. Jones, Jr.

[22] Filed:

Sept. 16, 1974 Attorney, Agent, or FirmOwen & Owen Co.

ApplL No.: 506,031

[57] ABSTRACT A tool for extracting the base of a broken light bulb from an electric socket is disclosed. The tool has a plurality of pointed knife-like blades which are pivotl C t Um 21. 55 [l [58] Field of Search........,......... 81/72; 30/103, 108;

294/95, 97, 93 ally mounted within the tool to swing downwardly and radially outwardly, thus defining a radially expanding arcuate movement, for engaging the inner surfaces of a light bulb base from which the globe has been broken off or removed.

[56] References Cited UNITED STATES PATENTS 295,307 3/1884 Towne 30/108 819,598 5/1906 30/108 4 Claims, 7 Drawing Figures 1 LIGHT BULB BASE EXTRACTORI BACKGROUND OF THE INVENTION The invention relates to tools for removing the bases of broken light bulbs from their sockets, and more particularly to an improved extracting tool which employs outwardly and downwardly pivoting blades to engage the inner surfaces of the base.-

A variety of light bulb base removing tools are known. See, for example, US. Pat. Nos. 1,983,411,

2,516,650, 2,721,492 and 3,797,055. See also US. Pat.-

No. 1,231,262 relating to an internal expansible wrench. Most of the tools, however, have been unwieldly to operate and difficult to insert into tight internal engagement with the lamp base. Nearly all of the prior art lamp base extractors known to applicant include only two gripping points which, when forced against the interior surfacesof a lamp base, tend to bend the thin metal lamp base into an oblong shape, thus tightening the base into the socket and making extraction more difficult. Most lamp base extractors have been primarily or entirely electrically conductive metal, providing opportunity for electrical shock during operation. In addition, several of the known lamp base extractors involve fairly complex mechanisms which seem unnecessary in light of the present invention described below.

SUMMARY OF THE INVENTION The present invention provides a light bulb base extractor which is relatively simplein construction and generally more effective and easily used than prior lamp base extractors. The tool of the present invention includes a plurality of peripherally spaced pointed knifelike blades pivotally mounted within the upper end of said tool. When a knob at the bottom of the tools handle is turned in a clockwise direction, an internal threadedshaft rotates to push upwardly an internal nut member or spool to which the blades are pivotally connected. The blades are pivoted downwardly and outwadly, thus definingan arcuate radially expandthe end of the tool, the tool is forced upwardly into the light bulb base as the blades engage the inner surfaces of the base, providing tight gripping contact between the tool and the base to facilitate easy removal of the lamp base from the socket.

In order to prevent dangerous electrical shock during the removal of a light bulb base, which may occur if power is connected tothe lamp socket for some reason,

the exposed outer surfaces which would be gripped by the user of the present tool are of a non-conducting material such as plastic, with the exception of the knife blades themselves which are out of reach of the operator when the tool is being used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially sectioned elevational view of a light bulb base extractor according to the invention, shown in engagement witha light bulb base;

FIG. 2 is a sectional view taken along the line 2 -2 of FIG. 1; I

FIG. 3 is a view similar to FIG. 2 but with the knife blades of the extractor withdrawn;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 2;

FIG. 5 is a partially sectioned plan view of the extractor taken along the line 5-5 of FIG. 3;

FIG. 6 is a perspective view of a threaded spool which forms a part of the light bulb base extractor; and FIG. 7 is a perspective view of a blade retaining ring which forms a part of the tool.

DESCRIPTION OF THE PREFERRED EMBODIMENT a rotating knob 18 which controls the position of the blades 16. The terms upper and lower, as used herein and in the appended claims, refer to the light bulb base extractor 10 as viewed in FIGS. 1, 2 and 3.

FIGS. 2 and 3 show the construction and operation of the lamp base engaging knife blades 16 of the tool 10. The blades 16, of which four are provided in this preferred embodiment, are pivotally connected to an internal spool or nut member 19 and extend outwardly through slots 20 in the upper-stem 14. The spool 19 is axially movable within an inner bore 21 of the upper stem 14, which is preferably formed along with the han- I dle 13 from a single piece of material. As FIGS. 2 andv 3 show, the spool 19 is in threaded engagement with a central rotatable shaft 22, the rotation of which effects adjustment of the axial position of the spool 19. The

lower end of the shaft 22 is connected to the rotatable V knob 18 at the lower end of the tool 10, as shown in FIG. 1. A central bore in the upper end cap 17 of the tool provides a bearing in which the upper end of the shaft 22 resides. Axial movement of the shaft 22 is prevented by the position of the knob 18 against the lower end of the handle 13 and by a stop 23 provided on the shaft 22 just above the lower surface of the bore 21. As

shown in FIGS. 2 and 3, the stop 23 may comprise a pair of nuts tightened together on the threaded portion of the shaft 22, and a washer 24 may be provided to aid rotation of the shaft.

Theshaft 22' and the spool 19 are preferably provided with aleft-handed thread pattern so that a clockwise rotation of the knob 18 and the shaft 22 will move the spool 19 upwardly to rotate the knife blades 16 downwardly into their engaged position. As indicated in FIGS. 2 and 3, the upward movement of the spool 19 j moves the blades 16 from their initial upwardly inclined, retracted position shown in FIG. 3 toward the horizontal position 'of FIG. 2 by forcing the upper surfaces of the blades 16 against the lower surface of the end cap 17 as the spool 19 advances. Thus, the four pointed knife blades 16 are caused to pivot downwardly and outwardly to engage the interior of a light bulb base.

The pivoted connection of the four knife blades 16 to the spool 19 is shown in FIGS. 4, 6 and 7. A retaining ring 26 which passes through a pivot point 25 in the in-.

terior end of each of the knife blades 16 is situated within an annular groove 27 in the spool 19. The annular ring 26 is fastened to the spool 19 preferably by soldering, but any suitable retaining means may be used. The spool 19 also includes grooves 28 normal to the annular groove 27 for receiving the blades 16 and allowing pivotal movement therein.

As FIG. 5 illustrates, the end cap 17 of the tool is preferably connected to the tubular portion of the upper stem 14 by means of bolts 29 which are threaded into the end cap 17.

In operation of the light bulb base extractor 10, the tool is first inserted into a light bulb base 11 with the blades of the tool fully retracted as shown in FlG..3. In this position the knob 18 and the shaft 22 are in their full counterclockwise positions. Although it is advisable for the operator to shut off power to the light socket 15 before-inserting the tool within the light bulb base 11, he will nonetheless be protected against electrical shock even if the power is left on, because of the non-conductive end cap 17, upper stem 14, handle 13 and knob 18 of the extractor 10.

With the tool pushed fully into the center of the light bulb base 11, the operator holds the handle 13 of the tool with one hand and rotates the knob 18 in a clockwise direction with his other hand. As discussed above, this causes the pointed knife blades 16 to be rotated outwardly and downwardly into' engagement with the interior surfaces of the light bulb base 1 1. As the knives 16 engage the basev 11, the tool'10 is urged upwardly into a tighter contact between the end cap 17 of the tool and the light bulb base 1 1. This creates a tight, stable five point gripping contact between the tool 10 and the lamp base 11. The tool need not be steadied as it is rotated by its handle in a counterclockwise direction to remove the lamp base 11 from the socket 15, since the tool 10 is so securely engaged within the lamp base 11. Moreover,, the light bulb base 11 does not distort and jam within the socket 15 under the pressure of engagement by the extractor 10, since four blades 16 are provided for even gripping of the interior of the lamp base 1 1 and little outward expansive force is needed to provide a grip sufficient to unscrew the lamp base 11.

When the lamp base 11 has been removed from the socket 15, the knob 18 of the extractor 10 is rotated in a counterclockwise direction to draw the internal spool 19 downwardly within the tool. This causes the knife blades 16 to pivot upwardly by contact of the lower edge of each blade 16, at a point spaced outwardly from the pivot point 25, against the confining surface defined by the bottom of the slot 20 as shown in FIG. 3. As the blades 16 pivot inwardly and upwardly, the tool 10 is drawn downwardly away from the core of the light bulb base 11 and the contact of the pointed blades 16 with the interior surface of the light bulb base 11 is terminated, so that the lamp base 11 may be withdrawn from the tool 10 and discarded.

As previously pointed out, the handle 13, knob 18 and preferably the upper stem 17 of the tool are desirably fabricated from non-conductive materials such as plastic or even wood to eliminate any possibility of electrical shock to the user. In addition, the end cap 17 may also be composed of non-conductive material so that a short cannot occur within the broken bulb base between the sides of the bulb base 1 1 and other interior filaments, etc., which may partially be exposed within the base itelf and will be contacted by the end cap 17.

The above described preferred embodiment provides a light bulb base extractor which is effici ent, safe and economical to manufacture. Various other embodiments and alterations to this preferred embodiment may be made without departing from the spirit and scope of the following claims.

lclaim:

1. A light bulb base extractor, comprising a handle, an upper stem connected to the handle, a plurality of lamp base engaging pointed blades annularly disposed within the upper stem, and means for pivoting said pointed blades outwardly and downwardly with respect to said upper stem into a radially expanded position in engagement with the inner surface of a light bulb base so that as said blades engage the interior of the light bulb base, the upper stem of the extractor is pushed upwardly against the core of the light bulb base, said means comprising a threaded rotatable shaft within the upper stem, a rotatable knob connected to the shaft adjacent the handle, an internal spool within the upper stem in threaded engagement with the threads of the shaft, said blades being pivotally connected to the spool with the pivot axes of the blades tangential to a circle concentric with the rotatable shaft, and upper and lower guide means above and below each blade for causing the blades to pivotally retract into an upwardly inclined position when the spool is drawn downward by rotation of theknob and shaft in one direction and for causing the blades to pivot outwardly and downwardly toward a horizontal position when the spool is moved upward within the upper stem of the extractor during rotation of the knob and shaft in the opposite direction.

2. The light bulb base extractor of claim 1 wherein said lower guide means comprises the lower boundary of a slot formed in the upper stem about each of said blades, and said upper guide means comprises a lower surface of said end cap.

3. The light bulb base extractor of claim 1 wherein said blades are pivotally connected to said spool by means of a common annular ring disposed in the path of said circle concentric with the rotatable shaft, said annular ring being affixed to said spool.

4. The light bulb base extractor of claim 1 wherein the threads of said shaft and spool are lefthanded whereby said knob may be rotated in a clockwise direction to move the blades into engagement with a light bulb base. 

1. A light bulb base extractor, comprising a handle, an upper stem connected to the handle, a plurality of lamp base engaging pointed blades annularly disposed within the upper stem, and means for pivoting said pointed blades outwardly and downwardly with respect to said upper stem into a radially expanded position in engagement with the inner surface of a light bulb base so that as said blades engage the interior of the light bulb base, the upper stem of the extractor is pushed upwardly against the core of the light bulb base, said means comprising a threaded rotatable shaft within the upper stem, a rotatable knob connected to the shaft adjacent the handle, an internal spool within the upper stem in threaded engagement wIth the threads of the shaft, said blades being pivotally connected to the spool with the pivot axes of the blades tangential to a circle concentric with the rotatable shaft, and upper and lower guide means above and below each blade for causing the blades to pivotally retract into an upwardly inclined position when the spool is drawn downward by rotation of the knob and shaft in one direction and for causing the blades to pivot outwardly and downwardly toward a horizontal position when the spool is moved upward within the upper stem of the extractor during rotation of the knob and shaft in the opposite direction.
 2. The light bulb base extractor of claim 1 wherein said lower guide means comprises the lower boundary of a slot formed in the upper stem about each of said blades, and said upper guide means comprises a lower surface of said end cap.
 3. The light bulb base extractor of claim 1 wherein said blades are pivotally connected to said spool by means of a common annular ring disposed in the path of said circle concentric with the rotatable shaft, said annular ring being affixed to said spool.
 4. The light bulb base extractor of claim 1 wherein the threads of said shaft and spool are lefthanded whereby said knob may be rotated in a clockwise direction to move the blades into engagement with a light bulb base. 